In 1992-94, an epidemiologic investigation of upper extremity (UE) musculoskeletal disorders (MSDs) was carried out in two automotive manufacturing plants. A cross-sectional study of 1,198 workers obtained both morbidity and exposure data, which also served as the baseline data for a one-year follow-up survey. Upper extremity disorders, defined both on the basis of symptoms and physical examinations, were found to be strongly associated cross-sectionally with an index of ergonomic exposure that included work pace, manual force, non-neutral postures and segmental vibration. In the one-year follow-up study, both the incidence of new disorders and the persistence of existing disorders from baseline were also associated with high ergonomic exposure to the upper extremity. All associations persisted after adjustment for numerous potential confounding variables. In the currently funded study, follow-up data on MSD morbidity and exposure have been collected about six years after the baseline survey. This competing continuation application seeks to extend the project period and budget for the currently funded investigation (R01 OH03514) in order to complete data collection and analysis. The overall objective is to seek to confirm and expand upon the previous associations of UE disorders with occupational ergonomic stressors. All eligible workers from the baseline study are being sought for interviews and examinations at the workplace, if still actively employed, or at home, in the case of retired workers. Morbidity information is obtained by standardized interview, screening physical examination, grip and pinch strength, vibrometry, and pressure pain threshold testing. The interviews also inquire as to changes in work history, medical and injury history, smoking, recreational activities, and other non-occupational covariates since the baseline interview. Exposure data on subjects' current jobs are collected by interview and observation, and by direct measurement for comparison in a subset of workers. The key substantive areas of investigation are: 1) determine changes in previously assessed exposures in the study jobs, from observation and self-report, and supplement these with observations of physical exposures in non-cyclical work and with new information on work organization characteristics of all study jobs; 2) estimate prevalence and cumulative incidence of new UE MSDs as a function of ergonomic exposures assessed at baseline (and at the one-year followup, for some workers) and in this survey; 3) estimate the persistence of previously identified disorders, again as a function of prior and current ergonomic exposures; and 4) examine work and health factors related to leaving employment and estimate the magnitude, if any, of the "healthy worker" selection effect operating in this population. In addition, methodological issues include the validity of psychophysical ratings of ergonomic exposures, short and long-term reproducibility of workers' recall of occupational exposures, and reproducibility and sensitivity of pressure pain thresholds relative to other signs.